In making telephone calls in traditional telephony systems, users typically have to dial the number associated with the callee. Typically, such numbers are entered through a keypad of a telephone, or alternatively, by pressing a speed-dial button. With some telephones, such as mobile telephones, a telephone directory may be displayable in the display of the telephone. A user may select an entry from the displayed directory to dial the corresponding telephone number.
In addition to calls over traditional circuit-switched networks, improvements in the bandwidth and speed of data networks have also enabled telephony sessions to be established over packet-based data networks, such as local area networks (LANs), wide area networks (WANs), the Internet, and so forth. Traditional communications over data networks include electronic mail, web browsing, file transfer, and the like. To enable reliable voice and other forms of streaming communications over data networks, various technologies and protocols have been developed.
An example of a device that enables voice communications over data networks is a computer system that is fitted with audio processing capabilities. Another example is a network telephone that has been designed with a network adapter to enable the telephone to be directly connected to the data network. Network telephones provide the familiar interface that users typically associate with telephones, but with the feature that communications can occur over a packet-based data network rather than a circuit-switched network.
With a network telephone, telephone numbers of callees are typically entered through the keypad, by activating a speed-dial button, or by selecting an entry from a telephone directory that is displayable in a display of the network telephone. With a computer system having audio processing capabilities, a more sophisticated graphical user interface is typically provided due to the larger screen size of the computer system. Telephone directories are displayed, with entries selected for dialing the telephone numbers of the callees.
Although many improvements have been made to make the process of dialing a telephone number more convenient, such as speed-dial buttons or selecting entries from a telephone directory, such features are still associated with various shortcomings. For example, a speed-dial button is programmed only on the individual telephone, and typically cannot be shared with other telephony devices. A telephone directory, such as an address book, is typically stored in a predetermined format set by the application program that created the directory. Typically, the telephone directory cannot easily be shared with other application programs.